It takes place in a closed hall (same used for basketball usually).. Poorly lit as you might know..

Now cause I can shoot pretty close to action, using a 35mm prime is a no brainer on my D7000 body..

But the challenge when I get to take the final group shot at the end..

With the 35mm I have obviously to step back quite a bit.. The group ranges from 30 to 80 persons depending on the event.. Mostly around the 30 (two rows, 15 persons wide) for quarterly ones, and up to 80 and 4 rows in the big annual events..

Shooting at a wide angle would enable short distance to subject (more light) and better flash performance.. However, some faces do tend to look funny at 16mm for instance.. Perspective issue.

At 35mm (50mm equivalent) is perfect for the perspective but less reflected in and the flash unit would struggle to fill the whole group (using SB-700)..

At the moment I have the 35mm prime and the 16-85mm to play with..But could anyone suggest out of personal experience the optimal balance for such a situation?